Biomarker Assay Design, Development, and Validation. We develop, validate, and implement assays for clinical specimens using electrochemiluminescence (ECL)-based immunoassays. This is the most sensitive and quantitative immunoassay technology platform today. The ECL platform is well suited for this ongoing task because it offers a high degree of flexibility, stability and reliability. It is capable of multiplex analysis to determine the levels of total and phospho-proteins in a single assay well using a limited amount of clinical specimens. Because clinical samples may vary dramatically, the ability to normalize these samples beyond total protein concentration is critical in generating statistically significant data with patient specimens. At the present, we developed, validated and utilized a wide range of biomarker assays, including angiogenic factors, cytokines, cell surface receptors, intracellular phosphoproteins and apoptotic biomarkers. II. Recently Completed Biomarker Studies Currently, we are engaged with 16 clinical protocols at NCI-CCR. For many of these clinical trials, we helped to design, develop, validate, and implement customized biomarker assays for correlative analytical studies. The evaluation of these biomarkers often constitutes a pivotal part of the clinical study for investigational agents. The following are some examples in the studies that we contributed with biomarker analysis at NCI.